Apparatus for interlacing multi-filament yarn



May 13, 1969 p/ [15, JR 3,443,292

APPARATUS FOR INTERLACING MULTIFILAMENT YARN- Filed May 31, 1968INVENTOR EIICEIE LOANS, JR.

ATTORNEY United States Patent 3,443,292 APPARATUS FOR INTERLACING MULTI-FILAMENT YARN Eugene L. Davis, Jr., Mechanicsville, Va., assignor to E.I. du Pont de Nemours and Company, Wilmington, DeL, a corporation ofDelaware Filed May 31, 1968, Ser. No. 733,476 Int. Cl. D02g 3/00; D04h17/00; D01h 13/26 US. Cl. 28-1 6 Claims ABSTRACT OF THE DISCLOSURE Afluid interlacer device is disclosed as particularly useful forproviding coherency in yarn which, as fed to the device, contains bothslack filaments and taut, load-bearing filaments. A pair of fluidpassages direct streams into a yarn passageway so that the streamsintersect at the 0pposite wall of the yarn passageway. Another fluidpassage directs a stream tangentially into the yarn passageway. The pairof intersecting streams opens the filament bundle and starts tointerlace the filaments. The tangential stream rotates the yarn bundle,presenting different portions to the interlacing streams, and the excesslength of slack filaments is taken up in loops or coils. Protrudingportions of broken filaments are also interlaced into the bundle. Theproduct maintains its unity without twist, has a uniform appearance, andmay have a desirable bulkiness.

The present invention relates to apparatus for producing interlaced,multifilament yarn and is more particular- 1y concerned with gas orliquid interlacers having both intersecting and tangentially-directedfluid streams.

The improved fluid interlacer of this invention has a straight yarnpassageway extending through a body member from a yarn inlet on one faceto a yarn exit on the opposite face, a pair of fluid passages fordirecting fluid streams across the yarn passageway so as to intersecteach other at the oppostie side of the passageway, and a third fluidpassage for directing a fluid stream approximately tangentially into theyarn passageway. The pair of fluid passages is in substantial alignmentwith a plane perpendicular to the longitudinal axis of the yarnpassageway and is located nearer to the yarn inlet than to the yarnexit. The third fluid passage is located nearer to the yarn exit than tothe yarn inlet and directs fluid in substantial alignment with a planeperpendicular to the longitudinal axis of the yarn passageway. Theeffectiveness of the third fluid passage may be improved by curving itin the same direction as the vortex produced by it. This passage and thepair of fluid passages are preferably located near to and at approximately equal distances on each side of the midpoint of the yarnpassageway. The yarn passageway is preferably of circular cross sectionand of a length at least several times the diameter thereof.

A thin string-up slot may be provided for inserting a running length ofyarn into the yarn passageway. When such a slot is present, itintersects the yarn passageway tangentially for the full length of thepassageway. The pair of fluid passages direct fluid streams to intersectat a portion of the yarn passageway wall which is not intercepted by theslot, and the tangential fluid passage is directed to produce a vortexwhich will retain the yarn in the yarn passageway rather than allow itto escape through the string-up slot.

Fluid interlacing devices have been described in Bunting and Nelson, US.Patent Nos. 3,110,151 and 3,115,691. Fluid twisters have been describedin Breen and Sussman, US. Patent No. 3,079,745; Clendening, Patent No.3,353,- 344; and Nagahara et al., Patent No. 3,206,922.. The use of asingle vortex jet for interlacing was disclosed in the above Bunting andNelson Patent No. 3,110,151. Fluid interlacing, fluid twisting andcombinations of the two have been used to give synthetic filament yarnsthe handling characteristics of true twisted yarns by preventingfilaments from separating from the yarn bundle. However, neither thefluid interlaceres nor the fluid twisters individually have beensuccessful in giving satisfactory handling performance to yarns whichhave a substantial number of stretched or slack filaments. Since thesefilaments are longer than their neighbors, they remain projecting fromthe surface of the yarn bundle as arch-like loops after usual fluidinterlacing or twisting operations. Broken filaments have also beendiflicult to bind firmly into the yarn bundle with prior fluidapparatus.

The present invention provides apparatus useful for forming the excesslength of stretched filaments into loops or coils, intermingling theexcess length into the body of the yarn bundle, and interlacing thestretched and unstretched filaments together so as to produce a cohesiveyarn of uniform appearance. The invention also provides apparatus whichis useful for gathering protruding portions of broken filaments andinterlacing them firmly into the yarn bundle. Other objects andadvantages of the invention will become apparent from the disclosure andclaims.

The invention will be more easily understood by reference to thedrawings, wherein:

FIGURE 1 shows an isometric view of a preferred fluid interlacingapparatus of this invention,

FIGURE 2 shows a cross-section perpendicular to the yarn passage atsection line 22 of FIGURE 1, the plane of the two intersecting fluidpassageways, and

FIGURE 3 shows a cross-section perpendicular to the yarn passage atsection line 33 of FIGURE 1, the plane of the tangential fluidpassageway.

Referring to FIGURE 1, yarn passage 4 is a cylindrical hole boredthrough body 9. Two fluid passages 5 enter yarn passage 4 near themidpoint of the length of yarn passage 4. The fluid passages aresupplied with fluid through plenum 6. Beyond the midpoint of the yarnpassage, tangential fluid passage 7 intersects the yarn passage. It issupplied with fluid through tube 8. Slot 10 extends the full length ofthe yarn passage and provides access for a running length of yarn 11 tobe threaded into the yarn passage.

Referring to FIGURE 2, the center lines of fluid passages 5 intersecteach other at the opposite wall of the yarn passage. The included anglebetween the center lines is designated as a. The bisector of this anglea will pass through the axis of yarn passage 4. Interlacing fluid can besupplied to plenum 6 by any conventional means.

Referring to FIGURE 3, fluid passage 7 enters yarn passage 4approximately tangentially and close to stringup slot 10. Passage 7 isstraight and is supplied with fluid through tube 8, which may be eitherstraight or curved. Passage 7 should be kept as short as possible whenit is used with a curved supply tube. When tube 8 is curved, the centerof curvature is on the same side of the center line of the fluid passageas the center of the yarn passage. Fluid passage 7 is preferably locatedclose to the edge of slot 10 so that the maximum velocity of the fluidstream curtains the slot and prevents yarn from being blown out ofpassage 4 through the slot.

In a preferred embodiment, yarn passage 4 has a diameter of 0.25 inchand a length of 1.25 inches. The planes in which the two sets of fluidpassages lie, indicated by section lines 2-2 and 33, are approximately0.17 inch on either side of the midpoint of the yarn passage length. Thediameters of fluid passages 5 are each 0.062 inch. Included angle a is30. The diameter of fluid passage 7 is 0.065 inch diameter and theinside diameter of tube 8 is approximately the same or slightly larger.The radius of curvature of tube 8 is 0.56 inch. Slot 10, which istangential to yarn passage 4, has a width of 0.031 inch.

In operating the apparatus of this invention, the fluid interlacer ispreferably positioned between suitable yarn forwarding means, i.e.,means capable of advancing the strand through the interlacer atcontrolled positive tension. Yarn is taken away from the jet at the samespeed at which it enters. Preferably, the jet is positioned so that yarn11 first encounters fluid passages and then fluid passage 7. The actionof the high velocity fluid streams from passages 5 opens the yarnbundle, separates filaments from each other and starts to interlacethem. Before the interlacing is completed, however, the filaments enterthe vortex flow created by the approximately tangential fluid passage 7.This flow rotates the whole yarn bundle and divided portions of thebundle, thus presenting the bundle to different portions of fluidstreams from passages 5. By the combination of actions taking place inthese two zones, the excess slack in stretched filaments is taken up inloops or folds, and then the interlacing action of the taut filaments iscompleted and binds the slack filaments into the interlaced bundlestructure, which maintains its unity due to frictional constraintbetween adjacent filaments even when the bundle is at zero twist.However, the product is not as compact as an otherwise similarinterlaced yarn which does not contain slack filaments and a desirablebulkiness may be imparted by intermingled slack filaments. In thepresent product, the taut, load-bearing, unstretched filaments do notform loops. There is little or no change in tenacity of the yarn afterjet processing.

A surprising feature of this apparatus is that, when all of the fluidpassages receive fluid at the same pressure, the majority of the fluidleaves the fluid interlacer at the end of the yarn passage which iscloser to the tangential fluid inlet. This occurs in spite of the factthat all fluid passages lie in planes perpendicular to the yarn passage,that fluid passages are nearly equally distant from the two ends of theyarn passage, and that the majority of the fluid enters the yarn passagethrough the fluid passages 5. The forwarding action of this flow patternapparently aids in gathering and folding the excess filament slack whilethe interlacing action is completed.

Preferably, interlacing is carried out as an adjunct to one or more ofthe common textile operations such as packaging, etc., thereby takingadvantage of existing yarn forwarding means. The minimizing of slackfilament loops protruding from the yarn bundle and the increasedcoherency of the entire structure provide greatly improved handlingproperties to the yarn in textile operations.

I claim:

1. In apparatus for fluid treatment of multifilament yarn to interlacethe filaments, an improved fluid interlacer comprising a body memberhaving a straight yarn passageway which extends from a yarn inlet on oneface of the body member to a yarn exit on the opposite face, a pair offluid passages for directing fluid streams across said passageway tointersect each other at the opposite side of the passageway, the twofluid passages being in substantial alignment with a plane perpendicularto the longitudinal axis of said yarn passageway and located nearer tothe yarn inlet than to the yarn exit, and a third fluid passage fordirecting a fluid stream approximately tangentially into the yarnpassageway in substantial alignment with a plane perpendicular to thelongitudinal axis of the yarn passageway, said third fluid passage beinglocated nearer to the yarn exit than to the yarn inlet.

2. Apparatus as defined in claim 1 wherein said yarn passageway has acircular cross section and a length at least several times the diameterthereof.

3. Apparatus as defined in claim 1 wherein said pair of fluid passagesand said third fluid passage are located near to and at approximatelyequal distances on each side of the midpoint of the yarn passageway.

4. Apparatus as defined in claim 1 wherein the center lines of said pairof fluid passages intersect at the opposite wall of the yarn passageway.

5. Apparatus as defined in claim 1 wherein said third fluid passage iscurved before it enters the yarn passageway.

6. Apparatus as defined in claim 1 wherein said body member has a thinstring-up slot for inserting a running length of yarn into the yarnpassageway, said slot intersecting the yarn passageway tangentially forthe full length of the passageway sothat the fluid streams from saidpair of fluid passages intersect at a portion of the yarn passagewaywall which is not intercepted by the slot, and so that the tangentialstream from said third fluid passage retains the yarn within the yarnpassageway.

References Cited UNITED STATES PATENTS 3,079,745 3/1963 Breen et a1.5734 3,110,151 11/1963 Bunting et a1. 57157 3,115,691 12/1963 Bunting eta1. 281 3,206,922 9/1965 Nagahara et al. .0.-- 57-34 XR 3,262,179 7/1966Sparling 281 3,333,313 8/1967 Gilmore et al 28-1 3,353,344 11/1967Clendening 5734 JOHN PETRAKES, Primary Examiner.

U.S. Cl. X.R.

